Which features of Latvian intonation are older than the corresponding features in Lithuanian?

In the context of the Baltic languages, Latvian is considered more archaic than Lithuanian regarding the intonations inherited from Proto-Baltic.1

Specifically, the following features of Latvian intonation are older than their counterparts in Lithuanian:

• Circumflex Intonation: The Proto-Baltic circumflex intonation has preserved its original falling character in Latvian, whereas it became rising in Lithuanian.1
• Acute Intonation: The Proto-Baltic acute intonation retained its rising character in Latvian, while it is falling in Lithuanian.1

In some instances, the Latvian acute intonation has shifted to a broken intonation due to stress retraction. While Latvian maintains these archaic intonational features, it is important to note that the language has undergone other significant innovations, such as the fixation of word accent on the first syllable.12